Groundbreaking new literature has demonstrated that this is a reality. Fragments of fetal DNA, or cell free DNA, are found in maternal blood as early as 5 weeks after conception. These fragments can be analyzed and used for prenatal genetic testing. This will undoubtedly revolutionize genetic testing, including gender identification, as we see it today.
Companies are now offering kits, sold over the internet, that can be used to obtain this information. These kits are able to pick up, from the plasma of pregnant women, the presence or absence of fragments of DNA from the fetus, which contain the Y chromosome. This Y chromosome determines if the child they are carrying is a male fetus.
Currently, this testing is not routinely done in the obstetricians office. Testing has not been officially approved by CLIA (Clinical Laboratory Improvement Amendments). Patients must find sources from the internet. There is no insurance reimbursement for these tests.
The advantages of having information about fetal DNA at such an early stage is tremendous. Parents can now screen for certain disorders that are specifically linked to a particular gender at a much earlier stage of pregnancy, in a reliable , safe, cheap, quick non-invasive fashion. Examples of diseases that can be
detected include Hemophilia, Duchennes muscular dystrophy and congenital adrenal hyperplasia. Paternity testing, Rh blood group typing, and fetal sex can also be accomplished through this testing.
During routine prenatal care, obstetricians routinely screen all pregnant women for chromosomal abnormalities. In particular, high risk women are considered to be:
• Those over the age of 35
• Any women with a family history or previous pregnancy with a genetic disorder
• Any pregnancy with a structural defect found on ultrasound or thickened nuchal region
• Abnormal maternal blood screening (alphafetoprotein testing and other biochemical markers).
For a woman carrying a gene for a sex linked disorder, it is common to undergo a procedure to determine the sex of the baby thereby determining if the unborn child will have the designated affliction. Commonly, a chorionic villus biopsy is performed, in which a small biopsy of the placenta is removed vaginally, at about 10 through 13 weeks, and chromosomal determinations are made. Alternatively, a woman can undergo an amniocentesis, usually performed at about 16 weeks. Both amniocentesis and chorionic villus sampling procedures have been associated with pregnancy loss. Ultrasound alone can be used to determine fetal sex non-invasively, but usually no earlier than 11 to 14 weeks, with about 86% accuracy at that time. The ability now to obtain information as early as 7 weeks, accurately, and noninvasively can be of tremendous clinical use. Finding a male fetus would qualify a patient for later invasive testing for the particular disorder, whereas finding out that a female fetus exists would obviate the need to take any further risk of testing for a sex linked disorder.
Further research can be expected in the future to produce other tests that will allow prenatal diagnoses of other chromosomal abnormalities and genetic disorders, all non-invasively. These routine tests will probably be incorporated by obstetricians in prenatal care of all pregnant women. Learning ways to distinguish fetal cells from maternal cells accurately is the real challenge. What types of concerns exist with this test?
New technology is always fraught with ethical, social, and cultural issues. Guidelines should be established to use information for clinical reasons and not for patient decision-making as to whether to electively terminate a pregnancy in an attempt to “balance a family.” The ability to map the entire fetal genome using this fetal DNA exists. Will people have the ability to screen for insignificant fetal traits and will personal values be the guidelines for a decision on terminating a pregnancy? Should there be government intervention regulating the use of this kind of testing? Should it be up to the medical provider to make the decision on who qualifies for testing and obtaining this kind of information. Many questions remain to be answered. Should this testing be commercially available to all consumers or should it be restricted to only those determined to be high risk for a sex-linked disorder? Is this a medical issue, a legal issue, a moral and ethical issue – or all of the above?
Feel free to respond with your opinions.